DE102007049689A1 - Stretch blow molding apparatus and method for producing preforms - Google Patents

Abstract

A device for the stretch blowing of plastic containers in a continuous single-stage process, having at least one injection rotor, with injection molds for preforms, which are fed via controlled valves from an extruder head and by way of a melt distributor from a central extruder, wherein the axis of the extruder is placed at least essentially in the axis of the injection pipe, and at least the extruder head and the melt distributor can be permanently and synchronously rotationally driven by the injection rotor. A method where, during the manufacture of each preform in the injection mold, injection molding phases and a compression molding or dwell pressure phase are combined and superimposed.

Description

The The invention relates to a device according to the preamble of claim 1 and a method according to the preamble of patent claim 25.

A known device according to DE 197 37 697 A to perform a single stage process, a central stationary extruder alternately feeds two spray rotors via a 2-way control valve. During injection molding, one is a spray rotor, while the other spray rotor is driven in rotation and transfers the preforms to a transfer star with cooling devices. In each spray rotor, a rotary distributor is arranged, which feeds the injection molds sequentially via controlled injection valves. The respective injection valve is opened only when the injection mold is previously closed and fixed with internal mandrel retracted into the end position.

At one off DE 31 24 523 A known device is a central extruder stationary. Sequentially controlled needle valves fill the cavities of four injection molds combined into a single unit. The spray rotor stops. The scope of the spray rotor four rotary-driven Blasrotoren are assigned. Transfer grippers engage the mouths of the preforms to transfer them in groups.

At the US Pat. No. 3,357,046 known device, two extruders are provided which operate continuously and are mounted diametrically opposite to a disc-shaped carrier. The carrier rotates about its axis to a respective dispensing position, stops in the dispensing position, or is at least substantially retarded before a strand exiting the extruder is separated and transferred to a stretch blow mold disposed thereunder.

At the DE 195 28 695 known apparatus for performing the single-stage process are used for transferring the preforms produced by injection molding expanding mandrels, which engage inside in the mouth of the respective preform. A stationary central extruder alternately feeds two injection molds reciprocable along an arcuate guide.

Of the Invention is the object of a device of the initially mentioned type for an efficient one-step process with to optimize high output. Part of the task is it also, an improved method of making the preforms specify yourself.

With the device to be created is intended to be continuous without delays or stops, one enabling small extruder size One step process with optimum utilization of the number of cavities to allow the device by low mold costs and to design a service-friendly modular design. According to the method the aim is to shorten the injection time and possible dead times, Gentle treatment of the melt ensures high preform quality to achieve while increasing the power per cavity, and to save energy through an optimized process flow.

The Asked object is achieved by the features of claim 1 and claim 25.

According furnishes through the at least co-rotating extruder head and the rotary distributor a high, possibly reinforced by a melt pump, realizable injection pressure with shortened process time, a small extruder size is sufficient and the possibly high number of cavities of the injection molds is optimally usable. These advantages are coupled with low mold costs, because the needle valves already belong to the machine module can, and with a high degree of serviceability due to a Modular construction of the device.

According to the method a shortening of the injection time and the dead times achieve, since the injection mold at the beginning of the process still does not need to be completely closed, d. h, the mouthpiece shape can still be open or off-hook. The first under Low pressure inflowing melt will not immediately cooled off from the cold inner spine, but can at least evenly in the bottom area of the later preform spread. A dosing unit is not needed and problems in the portioning accuracy are eliminated, as well as specific Reproduction problems. Low press forces are sufficient the adjustment of the inner mandrel out since during the compression holding phase no final shaping of the preform takes place. As a result, the melt is treated gently and results in Preform high quality. The power per cavity can be increased. Through the optimized process flow energy is saved. The possibly superimposed Repressive phase avoids fading problems.

at an expedient embodiment the entire extruder rotatable together with the spray rotor. The extruder may be from above or from below, preferably separable, be attached to the injection rotor.

In an expedient embodiment, the extruder, suitably arranged vertically above, comprises an extruder die the rotatably driven pressure section and a stationary feed section. The feed section is preferably fixed relative to the injection rotor by means of a torque support and enables the convenient supply of granules, for example via one or more stationarily arranged feed devices. A sealed rotary joint is provided between the pressure section and the feed section so that the extruder mouthpiece rotates with the pressure section while the feed section is stationary. Since the melt fed in by the extruder is brought to the injection molds by the shortest route, and there are no bottlenecks or appreciable deflection regions, a relatively small extruder size was sufficient because the process does not take place cyclically, as in the prior art, but continuously.

expedient has the rotary distributor, which with the extruder mouthpiece and the spray rotor, one with the extruder head, preferably decoupled, connected multichannel disk over, preferably heated, piping or hot runners with mounted in mold carriers of the spray rotor, controlled Needle valves are connected. It is only so long transmission paths before and is a permanent continuous flow of melt ensured.

There in the spray rotor various media, eg. B. a cooling medium, Compressed air, hydraulic medium, electrical control and supply current, a cleaning medium, and the like are needed, and the Supply ensured during operation of the spray rotor must be, is convenient to the extruder head remote side of the rotary distributor another rotary distributor arranged for these working media.

One A particularly important feature of the invention is that each Injection mold a bottom and hull shape, an openable, preferably cooled, mouthpiece shape and a axially adjustable by the mouthpiece shape, moving and preferably internally cooled internal mandrel. Thereby a precisely controllable temperature distribution in the preform is possible.

at a preferred embodiment has each injection mold a floor and hull shape and one together with an inside cooled and inner hollow mandrel relative to the ground and hull shape movable Mouthpiece shape that is openable. The melt injection valve is a metering needle valve that can be connected to the inner mandrel, to feed the cavity through the hollow inner spine. The Metering needle valve feeds a precisely predetermined dose of the melt a, wherein the dose is such that a fading in the preform is avoided. As the melt is fed through the hollow inner mandrel is, the soil and hull shape can be made simpler. The hollow inner spine is, as well as the bottom and hull shape inside cooled to optimize the temperature distribution in the preform.

at In this embodiment, the inner mandrel has a continuous one and in the area of the free end of the spine opening interior channel in, via the metering needle valve, the melt dose can be introduced into the cavity. In the inner channel is a Needle placed between a retracted feed position above a melt Nachdruckhub into one the mouth of the Inner channel closing closing position movable is. The total melt dose is controlled by the controlled metering needle valve introduced into the cavity, in three successive or adjoining steps. First a first portion of the dose is lifted out of the cavity Inner mandrel through the inner channel of the inner mandrel with low pressure in introduced the cavity, until there is a level achieved below the point of the mouth shape. Then it will be the inner mandrel lowered together with the mouth shape, wherein the initial melt filling under low Pressure by immersing the inner mandrel in the direction of the spot the mouth shape is displaced. Once the mouth shape is locked with the bottom and hull shape, and the internal spine its bottom end position has been reached and has been fixed, d. h., the cavity is tightly closed, the second part of the melt dose of Metering needle valve injected through the inner channel, up too the area of the mouth shape is filled. In This phase leaves a residual volume of melt in the inner channel. This residual melt volume is finally through Pushing the needle through the inner channel of the inner mandrel in one Pressing phase pressed into the cavity to a shrinkage submissions. The needle is pressed in until it finally the mouth of the inner channel of the inner mandrel closes.

expedient has the needle at the free end of a push-stamp with the diameter of the mouth of the inner channel. This Stamp presses the remaining melt volume from the inner channel into the cavity and finally closes the estuary. After completion of the preform, the Mouth shape together with the internal mandrel from the cavity lifted out, the preform remains on the inner mandrel. After that the mouth shape is opened and becomes the preform of Inner mandrel removed and transferred to the conditioning section. In this phase, the needle with the stamp is again so far pulled back that the inner channel of the inner mandrel for feeding the next melt dose is free again. It closes the stamp the inner channel upwards.

expedient are transportable to the injection molds in the conditioning section, preferably in the conditioning section rotatable, transfer expanding mandrels assigned to the removal of the preforms each from the open Mouthpiece shape are actuated. Every preform is gripped inside the mouthpiece and in the conditioning section Precisely conditioned to stretch-blow to have the right temperature profile, especially in the areas in those during stretching and bladder the strongest deformations occur while the mouthpiece already with the final shape in the injection mold and remains cool along the conditioning section.

Around the transfer of the preforms by the shortest route and adapted to simplify the rotational speed of the Blasotorors is an inlet star between the blowing rotor and the conditioning section with transfer elements for from the transfer expansion mandrels provided removed preforms.

at another, particularly important embodiment each injection mold each openable floor and Hull shapes and a, preferably cooled, mouthpiece shape as well as by the mouthpiece shape movable and off the injection mold removable internal mandrel on. The inner spine serves throughout the spraying process and in the conditioning section as a carrier for the preform, and is for example not cooled. However, every inner spine can be used on the way back into the spray rotor along the conditioning section cool down so far that it is not undesirable during the injection process Temperature influence exerts on the resulting preform.

expedient the removable inner mandrel is provided with an adapter part to which arranged on a link chain of the conditioning path transfer gripper Attack to remove or take over the inner mandrel with the preform and to transport along the conditioning section.

There the preforms are relatively firmly seated on the inner thorns, is at a expedient embodiment in or along the condition route a preform acceptance and transfer device provided, for example, a cam-controlled lowering device, with which the preforms of the inner thorns removable and to a Transferable with an inlet star of the blast rotor cooperating transfer star are.

at another, alternative and important embodiment is an openable and in each injection mold removable mouthpiece shape included. The one in the injection mold remaining inner mandrel is appropriately cooled inside. The mouthpiece shape comes together with the finished preform removed by means of transfer elements and at least along the conditioning section transports, preferably even into blow molds of the blower rotor, so that in this case each mouthpiece shape than at the preform permanent and used again in the blow mold transfer element serves.

in the With regard to fast and precise opening and closing Closing movements of the mouthpiece shape is in one expedient embodiment of the mouthpiece shape assigned to a pneumatic cylinder with a toggle mechanism.

The Closing force of the mouthpiece shape, however caused by blocking with the hull shape and / or the inner mandrel.

in this connection is expediently the inner mandrel by a hydraulic cylinder adjusted, which applies a high closing force, z. B. a hydraulic cylinder with a capacity of about 8 tons.

For the promotion of melt and a balancing effect of Melt flow can be useful in the extruder in the range the rotary joint be formed a buffering zone.

at An alternative embodiment is the conditioning section even variable in length. This can be done either by an adjustment or by replacement of the link chain and displacement of a deflection mechanism respectively.

in the With regard to compact dimensions of the device, the conditioning section be a rotor-shaped Konditionierkreis the circumference wearing a link chain with transfer expanding mandrels. alternative However, the conditioning section can be used as an elongated conditioning loop with a peripheral link chain and z. B. arranged thereon Internal mandrel transfer grippers be formed.

To the Thermal conditioning of the preforms is appropriate the conditioning section formed as a conditioning circuit the injection rotor and the inlet star at least one preform cooling station assigned.

at another embodiment is on the conditioning loop trained conditioning section in Rücklauftrum between the transfer star and the spray rotor at least one cooling station provided, with which the Innendorne cooled down on the way back become.

After all it is useful to solve problems from a division delay be able to cope, in particular as a conditioning form a trained conditioning section as a division delay section, in which the preform rotates.

According to the method In the production of high-quality preforms, the procedure has been such that initially only part of the cavity in the absence of the Internal mandrel under low pressure with melt from the needle valve is filled, up to a level below the mouth shape. Thereafter, this melt filling by adjusting the inner mandrel towards the end position below low pressure in the direction of the mouth shape displaced. Only then the inner mandrel is fixed in the end position, before remaining Melt volume is injected under elevated pressure.

This For example, by the needle valve when not in the Cavity and the end position adjusted internal mandrel open and melt metered under low pressure in the soil and the Hull form introduced. In the absence of the cool inner spine can the melt distribute cheap, before then the Inner mandrel under displacement of melt towards Mouthpiece shape adjusted to the end position and with the required Closing force locked with the mouthpiece shape becomes. Then the cavity is closed and will remain Melt volume metered under high pressure injected from the needle valve, until the preform is completed.

at an appropriate method variant is the Injection molding of the preform superimposed on a holding pressure phase, to prevent a loss. The cavity is first with still removed inner mandrel and lifted mouth shape Partially filled by the inner mandrel with low pressure. Then the inner mandrel is lowered with the mouth shape and finds the blocking takes place, with the initial melt filling displaced under low pressure by the dipping inner mandrel becomes. After blocking, the remainder of the melt dose is excluded the remaining melt volume in the inner channel of the inner mandrel, in the Cavity brought. After then the metering needle valve has been closed is, a needle is pushed through the inner channel to in the Nachdruckphase to press the remaining volume of melt into the cavity and to prevent such a loss.

According to the method Furthermore, even the mouthpiece form only closed or on put on the hull shape and / or the inner mandrel first retracted Be after in one part of the cavity without contact enough melt has been introduced with the inner mandrel is. This saves process time and initially allows low pressure.

embodiments of the subject invention will be explained with reference to the drawings. It demonstrate:

1 5 is a schematic plan view of a first embodiment of a device for stretch blowing plastic containers in a one-stage process;

2 a side view, partially in section of a spray rotor of the embodiment of 1 .

3 a detailed perspective view of an injection mold in the injection rotor of 1 .

4A to 4F Side views of individual steps in the sequence of movements of the embodiment of the injection mold of 1 .

5A to 5C Sectional views of an injection mold in three successive process steps,

6 a side view, partially in section of an embodiment of an injection mold 10 in the closed state, with respect to the illustration in 4A more details are highlighted

7 the injection mold of 6 in disassembled condition,

8th a schematic plan view of a further embodiment of the device,

9 a detail perspective view of the injection rotor of the embodiment of 6 , and

10A to 10D a further embodiment of an injection mold in four process steps.

In 1 is a device V for stretch blow molding of plastic containers, in particular PET bottles, shown in a one-step process in plan view. The individual components of the device V are arranged in modular construction compact to each other, and include a spray rotor 1 that with an at least partially co-rotating extruder 2 is combined and with an adjacent, here formed as Konditionierkreis conditioning section 3 cooperates, whose several cooling and / or heating stations 4 assigned. The conditioning section 3 cooperates with a feed star 5 , in turn, with a blowing rotor 6 for stretch blowing the container cooperates, from the finished container via a discharge star 7 in the direction of the arrow 8th be transported away. At the spray rotor 1 are z. B. in the peripheral area many injection molds 10 arranged. In the conditioning section 3 are transfer expanding mandrels 40 as transfer elements on movable arms of a pitch delay star 43 intended. The inlet star 5 also has transport or transfer elements from the spray rotor 1 upcoming preforms P to blow molding 50 the blower rotor 6 transfer.

According to 2 is the spray rotor 1 on a lower-side carrier 9 rotatably drivable arranged and with the in tie rods 28 having carriers arranged injection molds 10 stocked. In the center of the spray rotor 1 is a rotary distributor 11 arranged, which is a multi-channel disk 12 and to controlled needle valves 14 in the injection molds 10 running piping 13 (Hot runners with heating). Furthermore, in the embodiment shown below is centrally a media rotary distributor 15 for working media of the spray rotor 1 arranged (cooling medium, cleaning medium, heating medium, compressed air, hydraulic medium, control or supply current, and the like.).

Every injection mold 10 contains one by means of a hydraulic cylinder or a servo-operated closing spindle (hereinafter referred to as servo) 20 linear adjustable internal mandrel 16 , a one-piece or split floor and hull shape 17 and a split or openable mouthpiece shape 19 , Each mouthpiece shape 19 is by means of a pneumatic cylinder 21 and one in 3 shown toggle mechanism 30 opened or closed and by means of the hydraulic cylinder or servo 20 over the inner spine 16 locked in the closed position by Konusformschluss. Appropriate is the inner spine 16 cooled inside, and is also the mouth shape 19 cooled.

The central extruder 2 is essentially in the axis X of the spray rotor 1 and above (alternatively below), wherein at least the extruder mouthpiece with the spray rotor 1 synchronously rotated. Suitably, the extruder housing is in a high pressure part 23 with the extruder mouthpiece and a feed part 24 divided. The high pressure part 23 stands with the loading part 24 via a sealed rotary joint 22 in cooperation, such that the loading part 24 stationary stands when the high pressure part 23 rotates, for example via a torque arm 25 relative to the spray rotor 1 is held. Inside the casing of the extruder 2 there is at least one not further emphasized extruder screw 26 , with a relative movement to the high pressure part ( 23 ) rotates. The extruder is z. B. via at least one stationary arranged Granulatzuführschnecke 27 supplied with plastic granules.

3 illustrates the opened injection mold 10 to which through the columns 28 and a support plate 29 a mold holder of four sides access is possible. The pneumatic cylinder 21 has over the toggle mechanism 30 the mouth shape 19 already opened. At the top of the mouth 19 is a closing cone 31 recognizable, with a counter-cone in a support of the inner mandrel 16 cooperates to in the closed position of the mouth shape 19 build up the required closing pressure. The finished preform P is from a cavity 32 the hull and bottom shape 17 by a height adjustment movement of the mouth shape 19 pulled out and already to a not further highlighted transfer spreader 40 (or a laterally moved gripper) coupled to the preform P in the Konditionierstrecke 3 brings. In this embodiment, the hull and bottom shape needs 17 not divisible or openable.

The transfer expanding mandrel 40 engages in the mouth of the preform P, which is stable in this phase of operation and has a low temperature. The transfer expanding mandrel 40 will then star with the preform at a pitch delay 43 in the conditioning section 3 transferred, wherein the transfer expanding mandrel 40 rotates and the preform at the cooling stations 4 conveyed until the right temperature profile is achieved. Then take over grapple 41 at the inlet star 5 the respective preform and transfer this to a blow mold 50 the blower rotor 6 , During the further rotation of the blower rotor 6 the usual stretch blown process takes place.

In the 4A to 4F becomes a possible sequence of movements in the injection mold 10 shown.

In 4A the injection mold is still closed after completion of an injection process. The needle valve 14 locks off. A carrier 33 of the inner spine 16 locks the closed mouth shape 19 , The toggle mechanism 30 is closed.

In 4B is the inner spine 16 with his carrier 33 moved up. Now the mouth shape 19 together with the toggle mechanism 13 and the pneumatic cylinder 21 in the position in 4C moved up together with the preform. This will cause the blockage between the muzzle shape 19 and the hull and bottom shape 17 solved. Now the transfer expanding mandrel is moved up and the preform with the mouthpiece forming mechanism 34 in the transfer expanding mandrel 40 the conditioning section 3 hazards.

In 4D is the mouth shape 19 has been opened and the preform P is already sitting on the transfer expanding mandrel 40 who swings him out of the carousel.

In 4E is the mouthpiece shape mechanism 34 retracted and lowered and is the mouthpiece shape 19 closed. The inner spine 16 is lowered.

In 4F is the inner spine 16 reached in its lower end position and with the mouth shape 19 blocked, which in turn also with the hull and bottom shape 17 is blocked. The needle valve 14 opens and a new injection process begins.

The sequence of movements in the 4A to 4F may be useful to modify something to a method according to the 5A to 5C in which an injection molding operation is combined or superimposed with a compression molding process. This means that according to 5A unlike the 4E and 4F the inner spine 16 not yet driven down to the end position and possibly even the mouth shape 19 not yet put on and closed when with the opening of the needle valve 14 optionally off / timed, melt 35 At low pressure first dosed into the cavity 32 the soil and hull shape 17 flows. In contrast to the representation in 4F will now only with still open needle valve in 5B the inner spine 16 towards the end position in the melt 35 immersed, where he melt 35 towards the mouthpiece shape 19 repressed. The mouthpiece shape 19 is possibly only now or not yet with the hull and bottom shape 17 blocked and closed. In the following according to 5C becomes the inner spine 16 moved to the end position and by means of the carrier 33 with the cone 31 the optionally temporarily lowered, closed mouth shape 19 blocked, leaving the cavity 32 is closed. The required closing force is via the servo 20 generated. Residual melt volume is then injected under high pressure according to a conventional injection molding process.

The advantages of using the 5A to 5C described method are as follows:
The low-pressure melt 35 will not immediately from the cold internal spine 16 cooled, because this is still raised. There is a uniform spread of the melt, with a shortening of the injection time can be achieved. Furthermore, in this method results in a shortening of the dead time, since the injection mold need not be completely closed at the beginning of the process. A metering unit is not required, and there are no problems with the portioning accuracy in the compression molding. Likewise, there is no need for a reprint problem specific to compression molding. Since no final shaping takes place during the compression molding phase, there are only small pressing forces for the inner mandrel 16 required. Overall, the melt is treated very gently, resulting in high quality of the preform. Overall, there is an increase in performance per injection mold or cavity and can be saved by the optimized process energy. This method is appropriate for the device V according to 1 (or according to 8th ), but is also useful for other stretch blow molding or preform injection molding.

In 6 is the injection mold 10 with a bottom and hull shape 17 from a separate bottom shape 17b and a separate hull shape 17c trained, and sits the carrier 33 of the inner spine 16 in a carrier 48 that with a piston rod 47 the hydraulic cylinder or alternatively with the servo 20 connected is. In 6 is the injection mold 10 closed.

In 7 is the injection mold 10 shown disassembled. The inner spine 16 is with his carrier 33 from the carrier 48 pulled out. The inner mandrel has cooling channels 53 on that with cooling channels 52 in the carrier 48 communicate as soon as the carrier 33 is used. Further down in the carrier 33 a locking cone 54 for cooperation with the locking cone 31 the mouth shape 19 shaped, and is also in the hull shape 17c a locking cone 55 educated. The bottom shape 17b and the hull shape 17c are successively in a sleeve 49 introduced, which is adjacent to the needle valve 14 in the mold holder 28 . 29 is mounted and channels 51 for cooling and / or heating, which contains in the hull form 17c and the bottom shape 17b shaped channels 56 communicate. The toggle mechanism 30 is in 7 from the mouth shape 19 solved.

In the in 8th in a schematic top view shown another embodiment of the device for stretch blow molding plastic containers, in particular PET bottles, in a single-stage process, the respective inner mandrel is used 16 during the spraying process and along the conditioning section as a support for the preform P. In this case, the internal mandrel 16 not refrigerated inside.

To the spray rotor 1 with the co-rotating extruder 2 joins in 8th a conditioning section 3a as a conditioning loop with the link chain 43 is formed, which is also about the spray rotor 1 extends. The conditioning section 3a can, as with 37 indicated, be variable in length. At the link chain 43 are grippers 39 arranged, for example, in the direction of an arrow 46 along the conditioning section 3a are rotatable, and serve in 9 shown adapter parts 44 the inner thorns 16 to take.

In 8th is between the conditioning section 3a and the inlet star 5 a transfer star 42 arranged, for example, with grippers 40 (eg Spreizdornen) is equipped. The grippers 40 take over the preforms P of a takeover and transfer device 38 in the conditioning section 3a , The acceptance and transfer device 38 is for example a lowering device for the of the inner spikes 16 transported preforms. A cool station 4 between the transfer star 42 and the spray rotor 1 Can be used to cool the inner mandrels 16 on the way back into the spray rotor 1 be used. Further heating and / or cooling stations, not shown, can be used to condition the preforms at the inner mandrels 16 to be used. Optionally, the transfer star 42 Assigned to preform cooling stations. Also in 8th shown device V is composed in modular design of individual optionally combinable modules in a compact arrangement.

9 clarifies that in every injection mold 10 the soil and hull shape 17a divisible and openable, and even the mouth shape 19 in openable version contains. The inner spine 16 carries the adapter part at the top 44 on which the gripper 39 at the link chain 34 engages around the internal mandrel supporting the preform P. 16 from the opened injection mold 10 and in the conditioning section 3a to convict. If necessary, each internal spike 16 after lifting across to the link chain 34 ready gripper 39 method. In this case, the inner spine can 16 how to hold a floor mold. The soil and hull shape 17 can along with the mouth shape 19 by a pneumatic cylinder, not shown 21 and a toggle mechanism 30 be opened and closed. The blockage by the inner spine 16 via the hydraulic cylinder 20 , which provides appropriate cones and possibly locking pins for the required closing pressure and positive locking. The grippers 39 at the link chain 43 are designed to be the inner spine 16 in the spray rotor 1 and rotate along the conditioning path. The acceptance and transfer device 38 takes the brought to the desired temperature profile preform P from the inner mandrel 16 by peeling down and passes the preform to the transfer star 42 , Subsequently, the empty inner thorns 16 when returning to the injection molds 10 cooled.

On the spray rotor 1 is central and, for example, above by means of a torque arm hanging the co-rotating extruder 2 arranged according to the embodiment in 2 with the rotary distributor arranged under the extruder mouthpiece 11 from which the individual needle valves 14 below the injection mold 10 be supplied. The needle valves 14 belong to the machine module. The modular design is service-friendly.

In an alternative embodiment, not shown in detail, based on the 8th and 9 should be explained, do not serve the inner thorns 16 as a carrier of the preforms P on the way to the blowing rotor 6 but are the ones from the injection molds 10 removable openable mouth shapes 19 used for this. Each muzzle 19 may have an adapter part that of a gripper 39 grasped and with the closed mouth shape 19 with placed therein preform P from the injection mold 10 is led out. The mouth shape 19 remains closed and is only in the acceptance and transfer device 38 in the conditioning section 3a opened before marriage, for example, an expanding mandrel of the transfer star 42 the preform P takes over.

In another alternative, the closed mouth forms 19 even directly into the blow molds 50 the blower rotor 6 so that they also act as molded parts in the stretch blow molding process. However, then is not shown a return device for the mouth shapes 19 required.

For optimum utilization of stretch blow molding 50 in the blowing rotor 6 (the cycle time for stretch blow may be shorter than the cycle time for injection molding of a preform), it is convenient to the number of blow molds 50 a larger number of injection molds 10 so that the single-stage process runs under optimized conditions.

In the 10A to 10D become four process phases in another embodiment of the injection mold 10 illustrated. The injection mold 10 has a bottom and hull shape 17 (one-piece or two-piece) in which a part of the cavity 32 is defined. The mouth shape 19 is together with the inner spine 16 relative to the soil and hull shape 17 traversable. The inner spine 16 has in this embodiment a continuous inner channel 61 on, at the free end of the inner spine 16 at an estuary 59 ends. To a supporting part 58 the mouth shape 19 and the inner spine 16 are cooling channels 52 connected to the internally cooled internal spine 16 and optionally also the mouth shape 19 to be able to cool.

Also the bottom and hull shape 17 has not shown cooling channels. At the top of the inner spine 16 is a nozzle 56 provided, to which the melt injection valve is connected, which in this embodiment as a metering needle valve 14 is formed and each introduces a precisely measured dose controlled. In the inner canal 61 of the inner spine 16 is a needle 57 slidably guided, at the free end as a stamp 60 is formed, the relatively tight in the inner channel 61 is fitted. To the dosing needle valve 14 leads an unspecified highlighted heating channel for the melt.

In the in 10A shown process phase is with the inner mandrel 16 and closed mouth 19 from the dosing needle valve 14 over the inner canal 61 Melt into the cavity 32 placed under low pressure, which is a lower part of the cavity 32 fills. The needle 57 is in its upper feeding position, in which it is the inner channel 61 closes up and the flow connection from the metering needle valve into the inner channel 61 releases.

Then, between the process phases in 10A and 10B The Stamp 16 along with the mouth shape 19 lowered until the mouth shape 19 interlocked with the bottom and hull shape and the inner spine 16 have been fixed in its lower end position. At the same time, the plunging inner mandrel displaces 16 the melt 35 first to the top of the cavity 32 in the soil and hull shape 17 , Until then, not all the melt dose has been introduced.

In the process phase in 10B is the mouth shape 19 with the soil and hull shape 17 splinted. The needle 57 is still in the feeding position. From the dosing needle valve 14 Now the rest of the melt dose is introduced, so that the area of the mouth shape 19 is filled.

In the next process phase in 10C are the dosing needle valve 14 closed and the needle 57 been moved to a lower reprint position, the needle 57 with the stamp 60 remaining in the inner channel 61 so-called buffered melt volume from the inner channel 61 nachdruckt in the cavity, until finally the stamp 60 the estuary 59 of the inner channel 61 closes.

In the process phase in 10D is after the completion of the preform P of the internal mandrel 16 along with the mouth shape 19 relative to the soil and hull shape 17 been raised, the preform P on the inner mandrel 16 and in the mouth shape 19 stays and out of the cavity 32 is pulled out. After that, the mouth shape 19 opened and the preform P is removed and transferred to the conditioning section. At the same time or lagging the needle 57 pulled back to its upper feed position to the connection between the metering needle valve 14 and the inner channel 61 release. This is followed by the process step accordingly 10A ,

In an embodiment not shown to the 10A to 10D could be the mouth shape 19 also on the ground and hull shape 17 remain while the inner spine 16 is moved. To remove the preform P must the mouth shape 19 however, be opened beforehand so that the preform with the inner mandrel 16 from the cavity 32 can be pulled out.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 19737697 A [0002]
• - DE 3124523 A [0003]
• - US 3357046 A [0004]
• - DE 19528695 [0005]

Claims (29)

Device (V) for stretch blow molding of plastic containers, in particular bottles, in a continuous one-step process, which simultaneously involves the injection molding of preforms (P) in at least one rotationally drivable injection rotor ( 1 ), transferring the preforms via a conditioning line ( 3 . 3a ) to at least one rotary-driven blast rotor ( 6 ), and the stretch blow molding of the containers from the preforms (P) in the blowing rotor ( 6 ), with an injection molding ( 10 ) in the spray rotor ( 1 ) via controlled valves ( 14 ) from an extruder head and through a distributor ( 11 ) with melt ( 35 ) feeding, central extruder ( 2 ), characterized in that the axis of the extruder ( 2 ) at least substantially in the axis (X) of the spray rotor ( 1 ) and that at least the extruder head and the melt distributor ( 11 ) permanently and synchronously with the spray rotor ( 1 ) are drehantreib-bar. Device according to claim 1, characterized in that the entire extruder ( 2 ) is rotatably driven about its axis. Device according to claim 1, characterized in that the extruder ( 2 ) a pressure section comprising the extruder mouthpiece and rotatable about the extruder axis (US Pat. 23 ) and a stationary, preferably via a torque arm ( 25 ) relative to the spray rotor ( 1 ) fixed stationary, feed section ( 24 ), and that between the printing section ( 23 ) and the loading section ( 24 ) a sealed rotary joint ( 22 ) is provided, through which an extruder screw ( 26 ) extends therethrough. Device according to claim 1, characterized in that the distributor ( 11 ) a with the extruder head, preferably decoupled, connected multi-channel disc ( 12 ), via, preferably heated, piping ( 13 ) with mold carriers of the injection molds ( 10 ) mounted, controlled needle valves ( 14 ) connected is. Apparatus according to claim 1, characterized in that on the side facing away from the extruder head of the distributor ( 11 ) a rotary distributor ( 15 ) for working media of the spray rotor ( 1 ) is arranged. Device according to claim 1, characterized in that each injection mold ( 10 ) a soil and hull shape ( 17 ), an openable, preferably cooled, mouthpiece shape ( 19 ), and an axially adjustable by the mouthpiece shape, moving and preferably internally cooled inner mandrel ( 16 ) having. Device according to claim 1, characterized in that each injection mold ( 10 ) a soil and hull shape ( 17 ) and one together with an internally cooled and internally hollow inner spine ( 16 ) relative to the soil and hull shape ( 17 ) moveable, openable mouthpiece form ( 19 ) and that the melt injection valve is a metering needle valve ( 14 ) and to the inner spine ( 16 ) is connectable. Device according to claim 7, characterized in that the hollow inner mandrel ( 16 ) an opening in the region of the free mandrel inner channel ( 61 ), which via the metering needle valve ( 14 ) with melt ( 35 ) and that in the inner channel ( 61 ) a needle ( 57 ) between a retracted feed position via a melt Nachdruckhub into one the mouth of the inner channel ( 61 ) Closing closed position is movable. Device according to claim 8, characterized in that the needle ( 57 ) at the free end a Nachdrück-stamp ( 60 ) with at least approximately the diameter of the mouth ( 59 ) of the inner channel ( 61 ) corresponding diameter. Device according to claim 6 or 7, characterized in that the injection molds ( 10 ) along the conditioning section ( 3 . 3a ) transportable transfer expanding mandrels ( 40 ) associated with the removal of the preforms (P) in each case from the mouthpiece forms ( 19 ) are controlled controlled. Device according to claim 10, characterized in that between the blowing rotor ( 6 ) and the conditioning section ( 3 ) an inlet star ( 5 ) with transfer elements ( 41 ) for the transfer expansion mandrels ( 40 ) Removed preforms (P) is provided. Device according to claim 1, characterized in that each injection mold ( 10 ) openable bottom and hull forms ( 17 ) and a, preferably cooled, mouthpiece shape ( 19 ) as well as one through the mouthpiece shape ( 19 ) movable and from the injection mold ( 10 ) removable inner mandrel ( 16 ), which as a preform transfer element at least along the Konditionierstrecke ( 3a ) is transportable. Device according to claim 12, characterized in that the removable inner mandrel ( 16 ) with an adapter part ( 44 ) for at one also about the spray rotor ( 1 ) guided link chain ( 43 ) of the conditioning section ( 3a ) arranged transfer gripper ( 39 ) is provided. Device according to claim 12, characterized in that in the conditioning section ( 3a ) a preform acceptance and transfer device ( 38 ), with which the preforms (P) of the inner mandrels ( 16 ) removable and to one with an inlet star ( 5 ) of the blowing rotor ( 6 ) cooperating transfer esters ( 42 ) are transferable. Device according to claim 1, characterized in that each injection mold ( 10 ) an openable and removable mouthpiece shape ( 19 ) and a movable through the mouthpiece shape, preferably internally cooled, inner mandrel ( 16 ), and that the mouthpiece shapes ( 19 ) with the preforms (P) by means of transfer elements ( 40 ) in the conditioning section ( 3a ) at least along the conditioning path ( 3a ), preferably even into blow molds ( 50 ) of the blowing rotor ( 6 ), are transportable. Device according to at least one of the preceding claims, characterized in that the mouthpiece shape ( 19 ) via a pneumatic cylinder ( 21 ) and a toggle mechanism ( 30 ) and each have a closing cone ( 31 ) with the hull shape ( 17 ) or the internal spine ( 16 ) is axially splintable. Device according to at least one of the preceding claims, characterized in that the inner mandrel ( 16 ) via a hydraulic cylinder and / or a servo-driven threaded spindle ( 20 ) axially adjustable and in the closed position with the mouthpiece shape ( 19 ) or the mouthpiece shape ( 19 ) containing soil and hull form ( 17 ) is blockable. Device according to claim 3, characterized in that in the extruder ( 2 ) in the area of the rotary joint ( 22 ) an internal buffering zone is formed. Device according to claim 1, characterized in that the conditioning section ( 3a ) is variable in length. Device according to claim 1, characterized in that the conditioning section ( 3 . 3a ) either as a rotor-shaped conditioning circuit with a peripheral link chain and transfer expanding mandrels ( 40 ) or as an elongated conditioning loop with a peripheral link chain ( 43 ) and internal mandrel transfer grippers ( 46 ) is trained. Device according to claim 20, characterized in that the conditioning section formed as a conditioning circuit ( 3 ) between the injection rotor ( 1 ) and the inlet star ( 5 ) at least one preform cooling / heating station ( 4 ) assigned. Device according to Claim 20, characterized in that the conditioning section () formed as a conditioning loop ( 3a ) in the return strand between the transfer star ( 42 ) and the spray rotor ( 1 ) at least one cooling station ( 4 ) for Innendorne ( 16 ) assigned. Apparatus according to claim 1, characterized in that the conditioning section, in particular the conditioning section designed as a conditioning circuit ( 3 ), a pitch delay line in the transfer path from the injection rotor ( 1 ) to the blowing rotor ( 6 ) Are defined. Device according to one of the preceding claims, characterized in that associated with the extruder a melt pump is. Method for producing container preforms (P) from a plastic melt ( 35 ) in a cavity ( 32 ) an injection mold ( 10 ), which form a soil and hull ( 17 ), an openable and axially adjustable mouthpiece ( 19 ), and a temporally and distance-controlled axially into the cavity ( 32 ) adjustable moving internal mandrel ( 16 ) and via a time and path-dependent controlled injection valve ( 14 ) is fed, characterized in that the times and ways in controlling the designed as a needle valve injection valve ( 14 ) and the axial movement of at least the inner mandrel ( 16 ) are coordinated so that the injection molding of the preform in the cavity ( 32 ) before, during or after the final closure of the injection mold ( 10 ) is superimposed on a compression molding or post-printing phase. Method according to claim 25, characterized by the following steps: a part of the cavity ( 32 ) in the absence of the inner spine ( 16 ) under low pressure with melt ( 35 ), the melt filling is carried out under slight pressure by adjusting the inner mandrel ( 16 ) in the direction of its end position in the direction of the mouth shape ( 19 ), the inner spine ( 16 ) is fixed in the end position, and residual melt volume is under increased pressure in the cavity ( 32 ) injected. Method according to claim 25, characterized by the following steps: with internal mandrel not yet adjusted to the end position ( 16 ) the needle valve ( 14 ) and will melt ( 35 ) dosed under low pressure in the soil and the hull shape ( 17 ) below the level of the mouth shape ( 19 ), the inner mandrel ( 16 ) is displaced by melt ( 35 ) towards the mouthpiece shape ( 19 ) adjusted to the end position and with the required closing force with the mouthpiece shape ( 19 ) and residual melt volume is metered under high pressure via the needle valve ( 14 ) injected. Process according to claim 25, characterized net by the following steps: a part of the cavity ( 32 ) in the absence of the inner spine ( 16 ) under low pressure through an inner channel ( 61 ) of the inner spine ( 16 ) with melt ( 35 ), the melt filling is carried out under slight pressure by adjusting the inner mandrel ( 16 ) and the mouth shape ( 19 ) towards an end position in the direction of the mouth shape ( 19 ), the inner spine ( 16 ) and the mouth shape ( 19 ) are fixed in the end position, a residual melt volume is under increased pressure from the metering needle valve ( 14 ) through the inner channel ( 61 ) of the inner spine ( 16 ) into the cavity ( 32 ) is injected, and in the pressure phase is in the inner channel ( 61 ) of the inner spine ( 16 ) stored melt from the inner mandrel ( 16 ) into the cavity ( 32 ). Method according to at least one of claims 25 to 28, characterized in that the mouthpiece shape ( 19 ) first closed or on the hull shape ( 17 ) and / or the internal spine ( 16 ) is fixed in the end position only after being in the one part of the cavity ( 32 ) a predetermined volume of the melt ( 35 ) has been introduced under low pressure.